a test I made today shows that this lens gets sharper for each stop down, from 2.8 to 16. At 2.8 it's not sharp at all, at 8 it's acceptable but there is still a substantial improvement by going down to 16. This seems to be contrary to what Schneider and most people say.
I think my method of testing was robust, enlarger head raised to ca. 10x enlarging, focused on the grain, used one single pin sharp neg (135), did'nt move the easel. My enlarger : Durst M670 VC.
I should be grateful if anybody can comment or help to explain what I'm getting wrong. It's a pain if I always have to use f16 to get my images sharp.Thanks in advance